Slip Coefficient in High-Strength Bolt Joints Coated with Corrosion-Resistant Zn/Al Metal Spray Method

Abstract

In high-strength bolted joints, it is known that the corrosion of base material causes the reduction of slip resistance. In this article, tensile tests on slip-critical joints utilizing Zn/Al metal spraying corrosion resistance method, which can prevent corrosion and meet the required mechanical characteristics of bolted joints, were carried out. In addition, slip coefficient and surface roughness were calculated. The key parameters of specimens were surface finishing condition and thickness of coating with the identical geometry in all specimens. It is found from the results that the slip coefficient of the joints with coated finish after sand blast treatment as well as those of noncoated joints with only sand blast treatment were similar or superior to 0.45, which is a specification criteria of slip coefficient in friction-typed joints.